Prognostic Significance of the Proposed IASLC/ATS/ERS Revised Classification of Lung Adenocarcinoma in 514 Stage 1 Lung Adenocarcinomas (ADC)
A Yoshizawa, N Motoi, GJ Riely, M Kris, BJ Park, VW Rusch, WD Travis. Kyoto University Hospital, Kyoto, Japan; Cancer Institute Hospital JFCR, Tokyo, Japan; Memorial Sloan Kettering Cancer Center, New York, NY
Background: The International Association for the Study of Lung Cancer (IASLC), the American Thoracic Society (ATS) and European Respiratory Society (ERS), have proposed a revised classification of lung adenocarcinoma. There are no studies investigating the prognostic significance using the proposed criteria. We sought to investigate the usefulness of this classification to identify prognostically significant ADC subtypes.
Design: A total of 514 patients were classified as Adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), lepidic predominant non-mucinous (LPNM), acinar predominant (AP), papillary predominant (PP), micropapillary predominant (MPP), solid predominant (SP), colloid predominant (CP) and mucinous adenocarcinoma (MA). Statistical analysis was performed using SPSS version 17 with crosstable using Chi-square statistics. Survival analysis was performed using Kaplan Meier analysis for disease free survival (DFS) and Cox regression.
Results: We found 323F (63%) and 191M (37%) with 376 1A (73%) and 138 1B (27%); mean age 68 yrs (33-89 yrs). 5-yr DFS for males was significantly worse (77%) than that for females (88%, p=0.011); it was also worse for IB (75%) than for 1A (86%, p=0.001). Three overall prognostic groups for 5 yr DFS were identified: 1) 100% for AIS: n=1, MIA: n=7 and LPNM: n=28; 2) 85% for PP: n=143, 86% for AP: n=232 and 86% for MA: n=15 and 3) 69% for SP: n=66, 62% for MP: n=12 and 69% for CP: n=9 (p<0.001). In addition, survival was significantly worse for MA (76%) compared to LPNM (100%, p=0.014). In multivariate analysis stratified for stage, proposed IASLC classification, lymphatic invasion and sex were independent prognostic predictors of survival.
Conclusions: The proposed IASLC/ATS/ERS classification identifies prognostically significant categories of Stage I lung ADC. AIS and MIA are rare tumors at MSKCC, comprising less than 2% of all cases and LPNM accounted for only 5.4% of all tumors. These data support the proposal to use the predominant subtype for classifying the remaining 93% of our lung adenocarcinomas which were invasive.
Monday, March 22, 2010 1:00 PM
Platform Session: Section E, Monday Afternoon